The goal of this project is to evaluate the chronic toxicity and carcinogenicity of perfluorooctanoic acid (PFOA) in rats exposed in the diet. PFOA is used as a surfactant in foam fire-fighting agents and in the production of non-stick and stain-resistant products and is persistent in the environment. 2-Year chronic toxicity and carcinogenicity studies are in the histopathology/report writing phase. These studies include perinatal exposures (exposure during gestation and lactation). Humans are likely to be similarly exposed to these compounds through the environment. Perinatal exposure occurs during critical periods of development and can result in differences in toxicity/carcinogenicity as compared to exposure starting only from adulthood. The PFOA studies include 2-year exposures in both with and without perinatal exposure, to evaluate the effect of perinatal exposure. Keywords: toxicity, carcinogenicity, perinatal, perfluorooctanoic acid